Your car in a power outage

By the best of my estimation, I began writing this about five hours into a power outage at our cottage north of Winnipeg.

There was no, as far as we can tell, lightning in the area, but strong winds continue to blow, and it turns out knocked several things onto several power lines. The stuff in the fridge is cool for now, but too much longer and we’ll be packing coolers and heading home.

The idea of a backup generator is something that’s never far from my mind when we're out here. The distance to Winnipeg, the lack of any underground wiring and spruce, birch and poplar trees swaying in the wind make power outages likely, if not inevitable.

But what if, instead of a separate backup generator, which requires maintenance and fuel, you could just use your car?

In a pinch, even your standard, run-of-the-mill gasoline or diesel car could provide some power. Most cars come with 12-volt outlets you could use to run a portable cooler or some lights.

And many cars and SUVs now come with 110-volt power outlets, but they are designed for low-wattage accessories such as laptop chargers or small lights.

You wouldn't be able to hook it up to your house wiring and get power anywhere you needed, but it could provide enough power to keep a light on.

However, the new fleet of electric and semi-electric vehicles flooding the market — from the Nissan Leaf to the Chevrolet Volt to the Honda Accord Plug-in Hybrid — are giving a renewed push to the idea of storing electricity for use later.

That idea has been around for a while, but the components needed to fabricate such a system — a large stack of batteries and a smart electrical meter to manage flow of electricity from the power company to the home and batteries and from the batteries to the home and power company — are expensive.

But if you have a hybrid or an electric, you have a big stack of batteries already.

Part of the system is already in place: most electrics and plug-in hybrids are smart enough to be programmable to charge only when the power is cheapest: In some areas, power costs between peak demand times and lower demand times can be large.

The next step is making the power flow both ways, which is where a smart meter comes into play. The smart meter manages the choice of electricity, drawing from the power company when the costs are low or when no car is attached to the system, to drawing from the car when it's charged enough and prices are high or balancing the draw between car and power grid to save on costs.

The technology already exists, because it is already used by alternative-power customers using solar, wind or batteries (Smart meters are good enough that for these people, their solar or wind generators at times put power onto the grid, which generates a credit on their electricity bills).

Nissan demonstrated its V2H (for vehicle-to-home) system in 2012, and said the Leaf has the power to keep your home running for up to a day when fully charged. You just have to hope you don’t have to drive anywhere once that day is up.

Nissan is also developing a similar system for businesses, allowing companies to charge a fleet of Leafs when electricity is cheap and pull power from Leafs when it’s expensive. Either way, it can be programmed so the Leafs are ready when needed.

Another electric carmaker, Tesla, is leery of the idea, citing such issues as conversion losses (power is lost converting household current to direct current to charge the battery and again when the battery’s DC is converted back to AC) and reduced battery life from additional charge-discharge cycles.

Even Nissan seems to have cooled on the idea: since the July 2012 unveiling in Canada of the new Leaf’s potential as a backup power source, there have been no announcements.

There are a few caveats that make this not a do-it-yourself project, particularly if you don’t have a hybrid. The first being many of your household appliances draw considerable current.

The typical 750-watt refrigerator might only pull 8-10 amps at 120-volts household current, but thanks to Ohm’s law, we can see that 750 watts will draw more than 60 amps at a car’s 12-volt level, and that doesn’t include current needed to replace the power lost in converting 12 volts to 120 volts AC.

It’s made easier considering hybrid batteries run at 300-400 volts or higher, which translates into pulling only a few amps of current. But if 120 volts isn’t recommended for weekend warriors, 300-400 volts certainly isn’t, either.

As well, to use anything as a whole-home backup supply requires installing a transfer switch, which disconnects your home from the power company’s circuits when the backup is operating. Otherwise, your backup power will flow back to the power company’s circuits and could pose a hazard to staff working to end the outage.

As for systems such as these becoming common, a few things would have to happen: batteries would have to become more robust to withstand increased charge-discharge cycles and they’d have to become cheaper, both to permit less expensive electric vehicles and to permit a rethinking of battery warranties.

For now, considering the $30,000-plus price point of most electrics, spending $1,299 on a good Honda 2kW generator seems to make the most sense. It will power your fridge and a space heater or a light or two.

But the technology and the various explorations of different uses for electric cars suggests an interesting future is ahead. Especially since, as we’ve seen from cars such as the Tesla S or BMW i8, electric or electric-hybrid cars don’t have to be boring.